2003 Chevy Tahoe V8 Four Wheel Drive Automatic 168000 miles
The only way to get my hvac blower to turn off is to pull the 40 amp fues under the hood. Otherwise my batery will die. I can not change the speed of my fan either. But I can change it to defrost or any other path. What do you think might be the problem
You may be experiencing one of two faulty components. First I would check the blower motor relay located in the engine compartment fuse panel. This relay may have a stuck contact which is continualy sending power to the blower motor. An easy way to check this is to swap this relay with an identical relay located in the same fuse panel. For example if your horn relay is the same as your blower motor relay, swap them and test the blower motor. If it works you have a stuck relay. If the relay is not faulty, you may have a failed blower motor resistor. You can test this with an ohmmeter or you can visually inspect it as these resistors tend to have burn marks on them when they fail. The blower motor resistor is located under the passanger side dash. Remove the black cover under the dash. Immediately behind it is your blower motor and resistor assembly. The resistor has one electrical connector that has 7 wires going that go to the blower motor and is usually held in by 3 small screws. Remove the 3 screws and the resistor will come out. Look at the resistor circuit board. If you see any burn marks on the circuit board the resistor is faulty.
January, 10, 2009 AT 11:44 AM
I just looked for the relay and it is not in the under hood fuse pannel. Well at least I can not find it! When I get home later I will check the resitor like you said Thank you so far for all your help
January, 10, 2009 AT 2:33 PM
If you don't have relay in the fuse box then more than likely you have the set up that incorporates the relay with the resistor. When your take out the resistor your will see the relay mounted next to the electrical connector on the resistor. If you see no burn marks you may try hitting the relay on the ground with a swift hit straight down. It should knock the stuck contact loose. Regaurdless if you can get unstuck or not it is more than likely this component that is failing as the relay and reisitor are really your only components that control power to the blower motor.
February, 16, 2009 AT 1:36 PM
For the heater there is no relay. The relay and resistors are all in one. They are located under the dash. Just for your information.
January, 21, 2011 AT 3:43 PM
It is probably a little late, but if you replace the blower motor resistor/module (depending on what model yours has) it will fix your problem. $45 for a resistor(advance) $66 for a module(online)